HSC 4555 Lecture Notes - Lecture 9: Coagulation, Dendritic Cell, Lysis
Document Summary
The major organs and cellular components of the body"s defense against foreign antigens include: Tonsils, spleen, and lymph nodes b and t lymphocytes. Antigen-presenting cells bind to t cells which stimulate intracellular signaling pathways in the b cell and helper t cell that promote clonal expansion and differentiation. Activation of the helper t cell causes release of cytokines, which is required for b cells to proliferate and begin antibody synthesis (pg. Innate immune mechanisms do not require any previous exposure to mount an effective response against an antigen, and a wide variety of different antigens are recognized. Adaptive, or specific, immune mechanisms respond more effectively on second exposure to an antigen, and are highly restricted in the ability to recognize antigens (pgs. T helper cells are activated by these antigen-presenting cells and secrete cytokines that stimulate the production of wbcs in the marrow, initiate proliferation of mature b and t cells, and stimulate the phagocytic potential of macrophages and neutrophils.
